I am not a lawyer, but I believe the answer depends on how bitcoins are classified by the Securities and Exchange Commission.
If they're a currency then insider trading rules don't apply. But last time I looked the legal definition of 'currency' in the U.S. was the money issued by a recognized government. The only insiders for a currency are the people who issue it (I bet there are strict rules on trading of any kind by Treasury or Federal Reserve employees who have inside knowledge).
If Bitcoin gets classified as a commodity, then I'm not sure what rules apply. If an employee at Apple knows that the next generation iPad is going to use a lot of unobtanium, buys a bunch on the unobtanium exchange, then sells after the announcement for a profit are they guilty of insider trading? Probably...
If Bitcoin gets classified as a security, then I'm pretty sure insider trading rules would apply.
As always, if you're an employee at, oh, I dunno, Walmart and you know that Walmart will start accepting Bitcoin next March (I can dream, can't I?) and are tempted to buy a bunch of coin now I'd suggest you talk to a lawyer first.